Mechanism for actuating pattern or control drums in knitting machines, and knitting machines incorporating the same

ABSTRACT

A cylindrical knitting machine has pattern control drums actuated by respective cam followers, themselves actuated by driven cams rigidly set in a carriage moveable axially of the cylinder. By virtue of the construction of the carriage and the setting of the cams in it only one cam follower can be actuated at any one time. Movement of the carriage is caused through a positive drive mechanism by radial movement of a carriage having driving cams. Only one of these may be engaged at any one time by an actuator disc, of which the axial position is adjustable by a lever linkage for which the control is a chain driven by movement of the cylinder, the chain having stops of different heights. According to the height of the stop sensed by the lever linkage the actuator disc is set axially, causing a corresponding radial set of the driving cam carriage and hence a corresponding axial set of the driven cam carriage. This has five positions, a neutral or non-driving position and two on each side of that: the chain has stops of five heights and there are five driving cams.

United States Patent 1191 Comas m1 3,846,996 1451 Nov. 12, 1974 MECHANISM FOR ACTUATING PATTERN OR CONTROL DRUMS IN KNITTING MACHINES, AND KNITTING MACHINES INCORPORATING THE SAME [76] Inventor: Jorge Rectoret Comas, Calle Santalo, 96, Barcelona, Spain 22 Filed: June 1, 1972 r 21 App]. No.: 258,490

[30] Foreign Application Priority Data Primary Examiner-James Kee Chi Attorney, Agent, or FirmSteinberg & Blake [57] ABSTRACT A cylindrical knitting machine has pattern control drums actuated by respective cam followers, themselves actuated by driven cams rigidly set in a carriage moveable axially of the cylinder. By virtue of the construction of the carriage and the setting of the cams in it only one cam follower can be actuated at any one time. Movement of the carriage is caused through a positive drive mechanism by radial movement of a carriage having driving cams. Only one of these may be engaged at any one time by an actuator disc, of which the axial position is adjustable by a lever linkage for which the control is a chain driven by movement of the cylinder, the chain having stops of different heights. According to the height of the stop sensed by the lever linkage the actuator disc is set axially, causing a corresponding radial set of the driving cam carriage and hence a corresponding axial set of the driven cam carriage. This has five positions, a neutral or non-driving position and two on each side of that: the chain has stops of five heights and there are five driving cams.

10 Claims, 7 Drawing Figures PATENTEDHUV 12 1914 3.846396 sum 50? 5 MECHANISM FORACTUATING PATTERN OR CONTROL DRUMS IN KNITTING MACHINES, AND KNITTING MACHINES INCORPORATING THE SAME FIELD OF THE INVENTION This invention relates to mechanisms for actuating pattern or control drums in knitting machines, and knitting machines incorporating the same.

BACKGROUND OF THE INVENTION Various types of knitting machines have pattern or control drums actuated step-by-step, selectively and in opposite directions by advancing means actuated by pairs of cams carried on a portion of the machine which cams for actuating the advancing means function independently, so that it is possible that mechanical failure in any portion of the assembly may cause the simultaneous actuation of both cams; since the advancing means are generally pawl or ratchet devices operating drums are located at different levels, so that they are between the travel paths of both limbs in a central position of the cam member. The inner flanks of the said limbs are formed with cam tracks having-different radial heights and diverging outwardly, so that the displacement of the cam member in the one or other direction from the central position couples one of the tracks of the flanks thereof with a single one of the followers.

According to a further important feature of the invention, the driving cams are constitutedby two arms which are radially separated and the inner flanks of which carry cams stepped or shouldered in opposite directions, having entry ramps at the same side and which, on rotation, pass on both sides of a disc-like actuatingmeans displaceable by control means for coupling with each pair of cams which are radially opposite each other relative to the cylinder. The negative steps or shoulders separatingeach two ramps of one arm surround the positive steps or shoulders separating each of the ramps of the opposite arm, with an axial separation corresponding to the thickness of the actuating means.

Preferably, the two aforementioned slides are provided with rack teeth with which mesh transmission gears. The said gears may comprise, for example, a toothed wheel for each rack, and both wheels are fast in rotation and are of different diametenfor amplifying oppositely on one and the same escapement wheel, it

is inevitable that the mechanism will suffer damage.

SUMMARY OF THE INVENTION- The invention overcomes this disadvantage due to the fact that both the driving cams and the driven cams are arranged, rigidly and with no possibility for relative movement, in individual rigid units interconnected by motion transmission; the driving and the driven cams are arranged in their respective units in such manner that, when co-operating with the associated follower and actuating means, there is no possibility of the latter being simultaneously coupled with two opposed cams of each set.

The invention is, more specifically, applicable to circular machines comprising a'bed and a needle cylinder rotatable on the said bed, a station for supplying positional data, secured at a location thereof, a series of pattern or control drums secured on the bed about the cylinder, and mechanical memory means rotatable on the cylinder for transferring the positional data from the station for supplying the same to the various drums. In this case, an important feature of the invention resides in the fact that the memory means comprise a slider displaceable parallel to the axis of the cylinder and carrying the control cam unit, and a slider which is radially displaceable relative to the said axis and carries the driving cam unit; both slides are interconnected by means of the mechanism for transmitting the positional data from the driving cams to the driven cams, preferably this mechanism being a rack and pinion for each slider, the pinions being constrained to rotate together.

The driven cams are constituted, preferably, by a U- shaped member the limbs or arms of which are located at different positions along the axial direction of the cylinder, and the two opposite drive followers of the the displacement of the drive cams.

Finally, the disc-like. actuating means may be itself I actuated, by a single control chain having stops of varying heights, the heights being equal in number to the sum of the drive cam tracks.

DESCRIPTION OF THE DRAWINGS AND OF A PREFERRED EMBODIMENT:

FIG. 3 is an elevation in section approximately on the line III III of FIG. 1,

FIG. 4 is a bottom plan view of the mechanism, as-

suming withdrawal of the disc-like control means,

FIG. 5 is an elevational view of the mechanism for actuating the said control means,

FIG. 6 is a lateral-view showing means for advancin the pattern drum, and

FIG. 7 isa plan section of the previous Figure. Reference numeral 1 designates the fixed ring of the machine, on which are mounted, inter alia, the pattern drums and the means for step-wise actuation thereof (described later with reference to FIGS. 6 and 7). Of these FIG. 1 shows only the actuating cam followers 2 and 3, provided with contact rollers 4. Reference numeral Sdesignates a further fixed ring on the machine, constituting the circular slide means 6 on which rotates the mounting 7 for the cylinder, shown partly at 8 and having the schematically illustrated axis 8'. Mounted on the ring I, about the cylinder, are the various drum mechanisms, and the mounting 7 carries the mechanism for actuating the followers and the positional memory which is driven at a location on the periphery of the cylinder by the disc-like control means 9 actuated by the mechanism to be described with reference to FIG. 5.

In a support 10, secured to the mounting 7 by screws 11 extending through orifices 12, there is formed, by means of the adjustable straight edge 13, a dovetail slide 14 disposed vertically, for a carriage or slider 15 the cross-section of which is of dovetail shape and which, furthermore, is displaceable parallel to the axis of the cylinder. The upper end of the slider 15 has secured on its face directed outwardly of the machine, by means of screws 16 and centering pins 17, a steel block 18 of U-shape disposed in such manner that the two arms of limbs 19 thereof are vertically. spaced apart. The edges of the said limbs are profiled in the form of ramps ascending in the direction of displacement of the mechanism relative to the followers 2 and 3 (arrow 20,

FIG. 2), so that they constitute earns 21 and 22, the I distance 28'(FIG. 1) between the free faces of the contact rollers 4.

With this arrangement, the carriage described has five functional positions comprising: two end positions, shown in solid and broken lines in FIG. 1, in each one of which one of the rollers 4 will be moved by the cams 21 and 22; a central inoperative position wherein both rollers 4 will pass between the two faces 23,'and two in termediate positions between the latter and the first two, in each one of which one of the rollers4 will be moved by one of the cams 25 and .26. In the central position, the unit 18 does not actuate any of its followers 2 and 3, so that the drum mechanisms actuated thereby remain in that position in which they initially were; at each one of the positions located above the inoperative position, one of the cams 22 or 26 actuates the roller of the follower 3 in corresponding separate travel paths; in each one of the positionslower than the inoperative position the follower 2 is actuated with two separate travel paths. It is clear, therefore, that the pattern drum mechanism shown in FIGS. 6 and 7 may be actuated optionally in one or other direction and with advance of one or two teeth towards each side, as is conventional in this type of machine.

The lower portion of the slide 15 has a longitudinal toothed rack 29 with which permanently meshes a corresponding pinion 30 secured by means of the key 31 on a lateral neck 32a having a pinion of smaller diameter 32 free to rotate on the fixed pivot 33 (FIG. 3). The

latter is secured by means of a locking screw 34 in opposite walls of a support 35 of box-structure, adapted to be secured in position by means of screws extending through the orifices 36. The lower face of the said support 35 has a longitudinal portion (radial relative to the machine cylinder in the assembled position) which is turned-down rectangularly in such manner that, together with the straight edges 37 secured by the screws 38, it constitutes a slideway 39 for a further carriage or slider 40. On the upper face of the said slide is vertically and longitudinally secured, by means of screws 42 and centering pins 43, a plate 41 which has a mounting base strip 44; the upper edge of the said plate has rack toothing 45 permanently meshing with the pinion 32. Thus, it is clear that there is a fixed relationship between the displacements of the slider 40 and those of the carriage 15; the latter will be displaced vertically along a travel path somewhat longer than the horizontal displacement of the said slider for adopting any one of the five positions described, established by means of a retaining latch 46 (FIG. 2) applied against a series of notches 47, corresponding to the said five positions and formed in the edge of the slider 40, by means of a spring 48 which is held by a plug 49 and within the mounting 50 and secured by means of screws 51' to one of the sides of the support 35.

The lower face of the slider 40 has secured to it fo adjustment longitudinally, i.e. radially relative to the machine, a cam unit or group, designated by the general reference numeral 52, comprising a base plate 53 to which are secured, by means of screws 54 and 55 and centering pins 56, two earns 57 and 58 arranged to travel to both sides of the control disc 9 (as shown in FIG. 1); the base plate is secured to the 40 by means of screws 59 extending through orifices 60.

The inner face of the cam 57 has five shoulders 61 to 65 all extending from the same radial position relative to the machine cylinder, on the front side of the cam device. The said shoulders or steps constitute cams in the manner of inclined ramps terminating in crests 61a to 65a, the radial distances of which are those required for communicating to the slider 40 and hence to the carriage 15 any one of the five positions mentioned hereinabove. Froma comparison of FIG. 1 and 5 it will be appreciated that the said cams have radial dimensions which increase upwardly. The inner face of the cam 58 has a further five shoulders 67 to 71, also extending from the side from which the disc 9 is received in the device 52 and forming ramps of increasing height, terminating in crests 67a to 71a; in this case, however, the height of the said crests decreases upwardly and the assembly is so dimensioned as to obtain a radial position or height of the said crests such that there is between every two crests of the same level on I both earns 57 and 58 a constant distance corresponding to the diameter of the disc 9. Thus, in the position shown in FIG. 1, the disc 9is disposed between the crests 65a and 71a, maintaining the cam device 52 displaced to the maximum extent towards the right, so that the carriage 15 is in its lowermost position for the form of actuation involving the longer travel path of the follower 2; on upwardly displacing the disc 9, by means to be described later, the cam device 52 will be displaced step-by-step towards the left and the cam unit 18 will ascend through the other positions until it reaches the end, shown in broken lines.

- A further important feature of this mechanism resides in the fact that, in the two cams, the negative steps or shoulders, i.e., those forming a recess with the flanks 72 or 73 of the respective adjacent cams of greater height, surround the positive steps or shoulders of the other cam, i.e., the free edgesof the steps of the latter. In other words, between the flanks 72 and 73 of each pair of steps or shoulders (positive and negative), cooperating simultaneously with the disc 9, there is always a vertical distance which is greater than the thickness of the said disc, so that the latter is never able to simultaneously contact two steps the space between the crests of which is smaller than the diameter of the said disc 9. For example, if, with reference to FIG. 1, it is assumedthat the disc 9 is displaced upwardly, then it will be clear that, in a first phase, its right-hand edge will lose contact with the crest 71a prior to reaching the level of the flanks 72 of the cam 57; then, it will encounter the ramp 64, which will compel the assembly of the cam device 52 to travel towards the left until the two crests 64a and a contact diametrically opposite points on the disc. The same phases are reproduced between any other two positions, also during the descent of the disc.

The disc 9 (FIG. 5) rotates at the upper end of a vertical spindle 74 displaceable in a fixed guide 75, and the lower end of which has an adjustable stop 76 through the agency of which it bears-on one of the ends of a rocker 77 oscillating on a pivot 78, secured to a general support 79 forming a part of the machine structure. The opposite end of the. said rocker is connected to one ofthe ends of a further rocker 80, also oscillating on a pivot 81 secured to the support 79, through the agency of a link rod of adjustable length, having the general reference numeral 82 and constituted by a rod 83 of hexagonal section having two threaded end portions 84 coupled to associated tapped nuts 85, constituting the articulation heads of the rockers; a nut 86 screwed to one of the portions, permits thesecuring of the desired position of adjustment.

The other arm of the rocker forms a chain provided with the contact roller 87 bearing on a control chain 88 passing over the chain wheel 89. This chain is regulated by interposing between its normal of standard links further links provided with stops 90which may have five different heights according to the five operating positions to be adopted, during the functioning of the machine, by the previously described-mechanism, so that the length and arrangement of the chain will always depend on the nature of the operation for which the machine is prepared.

The sprocket wheel 89 rotates on a pivot 91 carrying a ratchetwheel 92 actuated step-by-step, forexample at each turn of the machine cylinder, bymeans of a cam 93 secured inconventional manner to one of the parts fastwith the said cylinder.- For this purpose, the general support 79 has secured to it, by -means of screws 94, two box structures 95 constituting a guideway for a bar 96 freely displaceable for longitudinal movement. One of the ends of the said bar has secured to it a pivot 97 for a contact roller 98 which is urged radially outwardly relative to the machine, to be actuated by the cam 93, for actuating a spring 99 tensioned between the posts 100 and 101 secured respectively to the bar and to one of the guide box structures; its rest position is determined by a stop 102 secured by means of the screw 103 to the general support and against which is applied the stud 104 secured to the bar 96. Secured at the other end of the said bar by means of screws 105 is a mounting 107 provided with a pivot 108 on which oscillates the pawl 109 for actuating the wheel 92.

Referring to FIGS. 6 and 7, the two cam followers 2 and 3, which are longitudinally slidable, are guided in associated slideways 110 formed in a base 111 secured by screws 112 on the fixed ring 1. Rotatable above the said base by conventional means (not shown) is the shaft 113 for a pattern drum 114 provided for example with replaceable patternjack sinkers 115 and on which are also secured two ratchet wheels 116, 117 the teeth of which are oriented in opposite directions.

The outer end of the base 111 has two pivots 118 and two posts 119, which are vertically secured and the other ends of which are fast with a stay plate 120 by means of the nuts 121. The two pivots serve for the pivoting of associated sleeves 122 and 123 each of which has a radial arm 124 and 125 located at predetermined levels and provided with adjustable stops 126 bymeans of which they take up the thrust of the end of a follower 2 or 3 respectively; externally of the said sleeves project arms 127 and 128'located at a further two separate levels and the ends of which terminate in articularf tion pivots 129 for associated pawls 130 and 131 apside.

plied against the wheels 116 and 117 under the action of the associated springs 132. A tooth 133 projecting from the inner face of each pawl bears, in the inoperative position (lower portion of FIG. 7), against the adjacent post 119'so as to keep the said pawl separate from its wheel, in order not to impede actuation in the opposite direction by the further pawl. I

Thus, it will be appreciated that actuation of the follower 2 towards the right bymeans of the cam unit 18 brings about actuation of the arm 124 and the displacement towards the left of the associated pawl 130 which I co-operates with the lower ratchet wheel 117 to rotate the pattern drum 114 invthe anti-clockwise direction with reference'to FIG. 7. Actuation of the. follower 3 produces a symmetrical mode of functioning resulting in rotation of the upper wheel 116 androtation of the drum in the opposite direction. Depending on the magnitude of the displacement of both pawls and according to the height of the cam of the unit 18 which has produced the action, the pattern drum will be displaced by the amount of one or two teeth towards the appropriate Thus it will be seen that with the abovedescribed structure of the invention,the parts 2 and-3 and 'the'elements which cooperate therewith form a pair of carn follower means operatively connected with the pattern drum means 114 for turning the latter in one direction or' the other depending upon which of these cam follower means is actuated by the driven cam means 1'8 which includes, in accordancewith the invention, the pair of cam portions 19 which are fixed with respect to each other and located apart from each other by a distance sufficiently great to prevent any-possible simultaneous actuation of both of the cam follower means 2 and 3. This driven cam means 18 is displaced by way of the carriage 15 and the rack-and-pinion' transmission described above to one of the above five positions for determining which of the cam follower means will be moved and the extent to which it will be moved, in response to positioning of the driving cam means 52 to one of its five possible positions referred to above by way of the positioning means which is formed by the cam disc 9. This positioning means 9 of course has also five possible positions for respectively determining the position of the driving cam means 52, and the positions of the positioning means 9 are determined by the detecting means 80,82, 77 (FIG. 5) which detects theinformation in the form of stops 90 of different heights carried by the information-containing chain 88 and which transmits this information to the positioning means 9 by locating the latter at a positionwhich corresponds to the information provided by way of the height of a particular stop 90.

The accessory details and other features which do not alter the essence of the invention will remain within the scope of the following claims.

What is claimed is:

1. In a circular knitting machine, pattern drum means, a pair of turning means operatively connected with said pattern drum means for respectively turning the latter in one direction or the other, a pair of cam follower means respectively connected operatively with said pair of turning means for respectively actuating the latter to turn said drum means in one direction or the other, rotary driven cam means supported for rotary movement about an axis of a cylinder of the knitting machine, said rotary driven cam means having a pair of cam portions for respectively cooperating with said pair of cam follower means to transmit movement through one or the other of said cam follower means to one or the other of said turning means for turning the drum means in one direction or the other, said pair of cam portions of said driven cam means being fixed to each other for rotation about the cylinder axis as a single unit and having with respect to each other a space which is too great for possible simultaneous actuation of both of said cam follower means, rotary driving cam means for assuming a plurality of positions to be respectively transmitted to said driven cam means for controlling the operation of the pair of cam follower means thereby, said rotary driving cam means also being supported for rotary movement about the axis of the cylinder of the knitting machine, transmission means extending between and operatively connected with said driving and driven cam means for transmitting movement of said driving cam means to said driven cam means so that the latter will assume a position determined by the position of said driving cam means, positioning means situated in the path of rotary movement of said driving cam means for engaging and positioning the latter, said positioning means itself having a plurality of positions and said driving cam means'responding to the position of said positioning means for providing through said transmission means a corresponding position of said driven cam means, information means containing data for controlling said pattern drum means, and detecting means cooperating with said information means and operatively connected with said positioning means for detecting the information in said information means and for responding to the latter information to displace said positioning means to a position corresponding to the detected information.

2. The combination of claim 1 and wherein said driven cam means has a pari of opposed end positions at one of which one of said cam portions actuates one of said cam follower means and at the other of which the other of said cam portions actuates the other of said cam follower means, and said pair of cam follower means respectively having free ends aligned with a space defined between said cam portions when said driven cam means is between said end positions thereof.

3. The combination of claim 2 and wherein each of said cam portions has a air of camming surfaces for respectively moving a cam follower means through different increments of movement and said driven cam means having four positions which include said pair of opposed end positions and two additional positions adjacent said pair of opposed end positions so that depending upon the position of said driven cam means, said drum means willbe turned in one direction or the other through one of a pair of different increments.

4. The combination of claim 1 and wherein said transmission means includes a pair of carriages respectively connected operatively with said driven and driving cam means, said carriages being movable in mutually perpendicular directions, and said transmission means including a pair of racks respectively fixed to said carriages, and a pair of pinions fixed to each other and respectively meshing with said-racks, so that in accordance with the diameters of said pinions a given transmission ratio willbe provided between said driving cam means and said driven cam means.

5. The combination of claim 4 and wherein said carriage operatively connected with said driven cam means is movable parallel to the cylinder axis while said carriage which is operatively connected to said driving cam means is movable radially with respect to the cylinder axis.

6. The combination of claim 5 and wherein said driving cam'means includes two sets of radially spaced stepped cams which are respectively stepped in opposite directions and which define between themselves a space inwhich said positioning means is received during rotary movement of said driving cam means, and the pair of stepped cams having with respect to each other a space which will provide for engagement of one or the other of-stepped cams by said positioning means in order to displace said driving cam means radially to a given position. v

7. The combination of claim 6 and wherein said positioning means is in the form of a cam disc which is received in the space between said stepped cams during rotary movement thereof.

8. The combination of claim 7 and wherein said stepped cams have oppositely inclined ramp portions defining between themselves a space which converges with respect to said cam disc during rotary movement of said driving cam means. i

9. The combination of claim 8 and wherein the axial dimension of said driving cam means as well as the axial dimensions of the steps of the stepped cams and their positions with respect to each other prevent said cam disc from being received at any time in the space between said stepped cams at a region where there is between the stepped cams a distance less than the diameter of said cam disc.

10. The combination of claim 9 and wherein saiddetecting means responds to said information means for displacing said cam disc parallel to the axis of the cylinder of the knitting machine, and said cam disc as well as said driving and driven cam means respectively having five positions which include between pairs of opposed end positions an intermediate position where said driven cam means will move past said pair of cam follower means without enaging the latter. 

1. In a circular knitting machine, pattern drum means, a pair of turning means operatively connected with said pattern drum means for respectively turning the latter in one direction or the other, a pair of cam follower means respectively connected operatively with said pair of turning means for respectively actuating the latter to turn said drum means in one direction or the other, rotary driven cam means supported for rotary movement about an axis of a cylinder of the knitting machine, said rotary driven cam means having a pair of cam portions for respectively cooperating with said pair of cam follower means to transmit movement through one or the other of said cam follower means to one or the other of said turning means for turning the drum means in one direction or the other, said pair of cam portions of said driven cam means being fixed to each other for rotation about the cylinder axis as a single unit and having with respect to each other a space which is too great for possible simultaneous actuation of both of said cam follower means, rotary driving cam means for assuming a plurality of positions to be respectively transmitted to said driven cam means for controlling the operation of the pair of cam follower means thereby, said rotary driving cam means also being supported for rotary movement about the axis of the cylinder of the knitting machine, transmission means extending between and operatively connected with said driving and driven cam means for transmitting movement of said driving cam means to said driven cam means so that the latter will assume a position determined by the position of said driving cam means, positioning means situated in the path of rotary movement of said driving cam means for engaging and positioning the latter, said positioning means itself having a plUrality of positions and said driving cam means responding to the position of said positioning means for providing through said transmission means a corresponding position of said driven cam means, information means containing data for controlling said pattern drum means, and detecting means cooperating with said information means and operatively connected with said positioning means for detecting the information in said information means and for responding to the latter information to displace said positioning means to a position corresponding to the detected information.
 2. The combination of claim 1 and wherein said driven cam means has a pari of opposed end positions at one of which one of said cam portions actuates one of said cam follower means and at the other of which the other of said cam portions actuates the other of said cam follower means, and said pair of cam follower means respectively having free ends aligned with a space defined between said cam portions when said driven cam means is between said end positions thereof.
 3. The combination of claim 2 and wherein each of said cam portions has a air of camming surfaces for respectively moving a cam follower means through different increments of movement and said driven cam means having four positions which include said pair of opposed end positions and two additional positions adjacent said pair of opposed end positions so that depending upon the position of said driven cam means, said drum means will be turned in one direction or the other through one of a pair of different increments.
 4. The combination of claim 1 and wherein said transmission means includes a pair of carriages respectively connected operatively with said driven and driving cam means, said carriages being movable in mutually perpendicular directions, and said transmission means including a pair of racks respectively fixed to said carriages, and a pair of pinions fixed to each other and respectively meshing with said racks, so that in accordance with the diameters of said pinions a given transmission ratio will be provided between said driving cam means and said driven cam means.
 5. The combination of claim 4 and wherein said carriage operatively connected with said driven cam means is movable parallel to the cylinder axis while said carriage which is operatively connected to said driving cam means is movable radially with respect to the cylinder axis.
 6. The combination of claim 5 and wherein said driving cam means includes two sets of radially spaced stepped cams which are respectively stepped in opposite directions and which define between themselves a space in which said positioning means is received during rotary movement of said driving cam means, and the pair of stepped cams having with respect to each other a space which will provide for engagement of one or the other of stepped cams by said positioning means in order to displace said driving cam means radially to a given position.
 7. The combination of claim 6 and wherein said positioning means is in the form of a cam disc which is received in the space between said stepped cams during rotary movement thereof.
 8. The combination of claim 7 and wherein said stepped cams have oppositely inclined ramp portions defining between themselves a space which converges with respect to said cam disc during rotary movement of said driving cam means.
 9. The combination of claim 8 and wherein the axial dimension of said driving cam means as well as the axial dimensions of the steps of the stepped cams and their positions with respect to each other prevent said cam disc from being received at any time in the space between said stepped cams at a region where there is between the stepped cams a distance less than the diameter of said cam disc.
 10. The combination of claim 9 and wherein said detecting means responds to said information means for displacing said cam disc parallel to the axis of the cylinder of the knitting machine, and said cam disc as well as said drivinG and driven cam means respectively having five positions which include between pairs of opposed end positions an intermediate position where said driven cam means will move past said pair of cam follower means without enaging the latter. 